The human innate immune system makes use of a number of germ-line encoded transmembrane and cell-surface proteins that recognize highly conserved molecular determinants, known as pathogen-associated molecular patterns (PAMPs), in pathogens including bacteria, fingi, and viruses. These proteins include the transmembrane glycoprotein toll like receptors (TLRs) and other related molecules including CD14, a glycosylphosphatidylinositol (GPI)-anchored cell-surface glycoprotein. Upon encounter with their cognate pathogen-associated molecular pattern-containing ligands (PAMP ligands), these molecules trigger a potent proinflammatory activation program, culminating in the activation of the adaptive immune response and healing.